The present invention relates to rollers for drum scanners, comprising a hollow cylindrical element which is rotatably mounted at its ends.
As compared to flat bed scanners, drum scanners comprise rapidly rotating rollers at the scanning and recording stations, the original which is to be scanned being secured thereto at the scanning station and the recording carrier thereto at the recording station. To obtain a high operating speed on such scanners, it is necessary to allow the roller to rotate rapidly which on the one hand leads to powerful centrifugal forces and because of the originals having the large format desirable nowadays renders a stable form of construction of the rollers necessary. In order that the recording carrier may be held on the roller even at high speeds of revolution, the roller has suction openings in its surface, which are in communication with the interior which is arranged to be connected to a vacuum pump so that a vacuum prevails within the roller. If desired, clamping devices may be omitted, which could lead to an undesirable imbalance at high speeds of revolution. In view of the high precision required during image processing, a high mechanical precision is equally of importance regarding the geometry of the roller surface. In the existing methods of roller production, be it by parting off from prefabricated tubes or by turning the rollers from the solid, comparatively high costs and a heavy form of roller construction are the result.